Random removal of the "compile" option from block context menu?

I noticed a few days ago that there is a new option in the context menu that pops up when you right-click a block or script that is called “compile”, with the tool-tip of “Make sure there are no errors, or Snap may freeze”. Today, I wanted to play around with this, as it seems like an updated version of the (compile ({}::ring)) block, which compiles scripts to Javascript, as long as said script did not include any loops.
But, I noticed it isn’t there, but I don’t recall Snap! updating any time recently, either. Did I just hallucinate it, or was it removed/disabled?
To be clear, I had no extra settings enabled when I found it, and no setting I can find brings it back.

i remember this being a thing for certain blocks

Turn on javascript extensions, then shift-click the setting and click JIT compiler support.

This does nothing.

Please attach some words to this.

it makes the block faster

I am aware of what the compile option does. How did you get it?

by right clicking on the block…

Are you trolling? Because you are not funny.

It’s only for these list HOFs:

map (()$addInput) over $list
keep items (<>$addInput) from $list
combine $list using (()$addInput)
find first item (<>$addInput) in $list

Ah, thank you. That makes sense, because I believe I found it on MAP

Well, I was going to say that it only worked on some blocks… but, I got ninja’d by redgeography snap.